#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=400;
typedef long long LL;
typedef pair<LL,LL> P;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
P a[maxn];
LL getdis(LL x1,LL y1,LL x2,LL y2){
    return abs(x1-x2)*abs(x1-x2)+abs(y1-y2)*abs(y1-y2);
}
int main(void){
   	cin.tie(0);std::ios::sync_with_stdio(false);
    LL n;cin>>n;
    for(int i=1;i<=n;i++){
        cin>>a[i].first>>a[i].second;
    }
    LL ans=0;
    for(int i=1;i<=n;i++){
        for(int j=i+1;j<=n;j++){
            for(int k=j+1;k<=n;k++){
                vector<LL>res;
                res.push_back(getdis(a[i].first,a[i].second,a[j].first,a[j].second));
                res.push_back(getdis(a[i].first,a[i].second,a[k].first,a[k].second));
                res.push_back(getdis(a[j].first,a[j].second,a[k].first,a[k].second));
                sort(res.begin(),res.end());
                ///cout<<res[0]<<" "<<res[1]<<" "<<res[2]<<endl;
                if(res[0]+res[1]+2*sqrt(res[0]*res[1])>res[2]){
                    ans++;
                }
            }
        }
    }
    cout<<ans<<endl;
   	return 0;
}
